Materials Literature
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An indexing program, TREOR, mainly based on trial-and-error methods is described. The program contains separate routines for cubic, tetragonal, hexagonal, orthorhombic, monoclinic and triclinic symmetries. Ten years usage has been analysed to improve the original program. For monoclinic indexing a specific short-axis…
X-ray diffraction, dielectric and differential scanning calorimetry studies have been performed on (CH 3 NH 3 ) 3 Sb 2 Br 9 crystals. The first-order structural phase transitions at 168 and 131K have been revealed to be related most probably to a freezing of the reorientational motion of CH 3 NH 3 + cations.
Comparison of x-ray-fluorescence-yield and electron-yield surface extended x-ray-absorption fine-structure spectra above the S $K$ edge for $c(2\ifmmode\times\else\texttimes\fi{}2)\mathrm{S}$ on Ni(100) reveals an order-of-magnitude higher sensitivity for the former technique. Thiophene (${\mathrm{C}}_{4}$${\mathrm{H}…
The interaction of a relativistic electron beam, travelling parallel to the surface of a semi-infinite medium, is analysed. The specific energy loss of the beam and the probability of excitation of surface and bulk modes in the medium are calculated. Beams both external and internal with the medium are considered, and…
The energy loss and differential probability of energy losses is calculated to all multipole orders for a charged particle moved uniformly past a sphere. The sphere's response is characterized by use of a local dielectric function.
Studies of phase formation in rapidly solidified Al-Mn alloys (composition range 18-22 at.% Mn) show that an icosahedral phase is replaced by another noncrystallographic phase, a decagonal phase. The decagonal phase is another example of quasicrystal: It has a noncrystallographic point group ($\frac{10}{m}$ or $\frac{…
Failure in materials is a complex phenomenon that is not well understood and is currently the subject of considerable research effort. Failure analysis in polymers is particularly complex because properties are not only functions of the chemical nature of the polymer but also highly dependent on the details of its phy…
For the past 50 years, protective and decorative coatings based on acrylic and methacrylic polymers have found increasing use in a variety of industrial and trade sale applications. This expanded usage has occurred because of the versatile and unique properties of these polymers and because of the development of large…
The technology of plasticizers fostered an enormous growth in use of plastics. It provided dozens of industries with a progressively widened spectrum of useful new materials whose flexibility (and concomitant physical properties) could be tailored to a need. It preceded by many years the appearance of synthetic commer…
In 1979 at the American Chemical Society/Chemical Society of Japan Chemical Congress in Honolulu, the Division of Organic Coatings and Plastics Chemistry sponsored a symposium entitled "Resins for Aerospace." This was an acknowledgment and tribute to the fact that the aerospace industry is a heavy contributor to the u…
The transport of small molecules, such as gases, vapors, or liquids, in polymers has been of intense interest to engineers and scientists for many years. Early studies of gas transport in elastomers were motivated by concerns about gas loss or interchange from automobile inner tubes, rubber balloons, cable insulation,…
The term "corrosion" has been applied to a wide variety of processes that have in common a degradation of the chemical or physical state of a material upon exposure to an aggressive environment. More commonly, the term is restricted to chemical degradation of a metal by its environment. The technological and economic…
The common central structural feature of organic macromolecules is the chain of covalently bonded atoms. Bond lengths and bond angles are rather rigidly fixed, but restricted rotation about single bonds permits a polymer chain to assume a wide range of three-dimensional conformations. At elevated temperatures, bond ro…
The first coherent, single-crystal, magnetic rare-earth superlattices of Gd-Y were grown by metal molecular-beam epitaxy. X-ray structural analysis showed that the superlattices have a composition modulation of two atomic-layer-sharp interfaces with the modulation amplitude approaching 100%. The magnetic properties ar…
We present a first-principles theory for the quasiparticle energies of semiconductors and insulators. The full dielectric matrix is used to evaluate the nonlocal, energy-dependent electron self-energy operator. Both local-field effects and dynamical screening are found to be essential for understanding quasiparticle e…
ABSTRACT A correlation which is a function of the reservoir temperature and the heptanes plus mole fraction has been developed to predict the maximum condensation during pressure depletion of retrograde condensate fluid reservoirs. A generalized equation of state has been used in phase behavior calculations. The phase…
ABSTRACT The chemical instability of Polyacrylamide polymer during both polymer and micellar-polymer flooding can seriously affect flood performance. Results of this study utilizing special laboratory techniques and long-term tests to simulate conditions typical of petroleum reservoirs show the effects of key variable…
Precise measurements of the X-ray attenuation coefficient of crystalline silicon have been made in the energy range 25 to 50 keV. The results are compared with theoretical predictions and earlier measurements. A systematic discrepancy between theory and experiment is observed. The most likely cause of the disagreement…
The electron-vibronic band with its no-phonon (NP) transition at 0.9351 eV which was recently detected in heat-treated silicon is strong after irradiation of silicon and has been studied in high-resolution photoluminescence. The defect exhibits a quasi-local mode of quantum energy h(cross) omega =66.3 meV which is obs…
Magnetocaloric experiments are performed in an attempt to decide whether S-shaped magnetization versus field curves M(B) of MnAs1−xPx-crystals (x = 0.08, x = 0.09) are due to magnetization processes or reflect a transition between two different magnetic states. Extra heats of formation which are observed under adiabat…